From mboxrd@z Thu Jan  1 00:00:00 1970
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From: Denis Kenzior <denkenz@gmail.com>
Subject: Re: U-Blox modem reconnect
Date: Fri, 01 Jul 2016 14:58:11 -0500
Message-ID: <5776CB53.2050609@gmail.com>
In-Reply-To: <5776444F.6070307@ilbers.de>
List-Id: <ofono.ofono.org>
To: ofono@ofono.org

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Hi Alexander,

On 07/01/2016 05:22 AM, Alexander Smirnov wrote:
> Dear all,
>
> could you please help me with the following issue. I use U-Blox
> SARA-U270 modem. I'm able to online it and connect to GPRS using both:
> connman and ofono-tests. The problem occurs when modem loses GSM link.
>
> What I did:
>
>   - Boot board with ofono 1.18
>   - activate-context & process-context-settings
>   - ifconfig shows ppp0, everything works
>   - Disconnect physical GSM antenna, network strength becomes 0 (in
> list-modems)

I doubt that this is a good way of testing out-of-coverage conditions. =

You'd probably need a proper network simulator to do that...

>   - Connect antenna, network strength becomes 40
>
> Problem:
>
>   After these steps, modem doesn't reconnect to GPRS, while
> list-contexts shows correct settings:
>
> [ /ublox_0 ]
>      [ /ublox_0/context1 ]
>          Username =3D t-mobile
>          AuthenticationMethod =3D chap
>          Protocol =3D ip
>          Name =3D Internet
>          Settings =3D { Interface=3Dppp0 Netmask=3D255.255.255.255
> Method=3Dstatic DomainNameServers=3D10.74.210.210,10.74.210.211,
> Address=3D10.23.6.118 }
>          IPv6.Settings =3D { }
>          Active =3D 1
>          AccessPointName =3D internet.t-mobile
>          Password =3D tm
>          Type =3D internet
>
> But I don't see ppp0 interface.

Run oFono with AT command logging enabled as well as debugging enabled. =

  See HACKING, 'Running from within the source code repository' section =

for instructions.

>
> An attempt to activate-context doesn't do anything, just empty output
> (with enabled debugging).
>
> Attempt to deactivate-context failed with:
>
> Error deactivating /ublox_0/context1:
> org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible
> causes include: the remote application did not send a reply, the message
> bus security policy blocked
>

Most likely because your modem's firmware itself has crashed.

>
> The only hard modem reset helps.
>
> Moreover, after antenna disconnect, there is no more cellular service in
> ConnMan. Only daemon restart helps.
>
>
> How should I handle lose GSM network events to keep ppp0 up? Why ofonod
> hangs with the steps mentioned above?
>

oFono itself is not hung, but the underlying modem has.  Remind me, is =

the SARA a serial based device or USB?

>

Regards,
-Denis

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